The use of chlorofluorocarbons or hydrochlorofluorocarbons as foam-blowing agents has been banned due to concerns that their release damages the ozone layer. More recently, foam-blowing (i.e., the addition of a volatile material to a polymeric mixture to cause a bubbled matrix which imparts insulation or cushioning value) has been accomplished through use of HFC-245fa; however, concern has been raised about the global warming potential (GWP) of this material.
One candidate to replace HFC-245fa as a foam-blowing agent is a liquid, trans-1-chloro-3,3,3-trifluoropropene, also known as HCFO-1233zd(E). This material also has potential use as a solvent, heat transfer composition, fire extinguishing/suppression composition, blowing agent, and compatabilizing agent. See, for example U.S. Pat. No. 6,844,475.
A second candidate for application as a single component foam-blowing agent is the gas, trans-1,3,3,3-tetrafluoropropene, also known as HFO-1234ze(E). See, for example, U.S. Pat. Nos. 7,230,146 and 7,485,760.
These two compounds represent the next generation of foam blowing agents. Several patents have been issued directed to processes for the production of these individual compounds, but the current invention discloses an integrated manufacturing process which economically co-produces both compounds starting from a single chlorinated hydrocarbon feed stock, namely 1,1,1,3,3-pentachloropropane (HCC-240fa).
The compounds of the present invention are part of a continued search for the next generation of low global warming potential materials. Such materials must have low environmental impact, as measured by low global warming potential and no substantial ozone depletion potential.
The preferred compounds of the present invention are environmentally acceptable and do not to contribute significantly the depletion of the earth's stratospheric ozone layer. The compounds and compositions of the present invention have no substantial ozone depletion potential (ODP), preferably an ODP of not greater than about 0.5 and even more preferably an ODP of not greater than about 0.25, most preferably an ODP of not greater than about 0.1; a global warming potential (GWP) of not greater than about 150, and even more preferably, a GWP of not greater than about 50.
As used herein, ODP is defined in the “Scientific Assessment of Ozone Depletion, 2002,” a report of the World Meteorological association, incorporated here by reference.
As used herein, GWP is defined relative to that of carbon dioxide and over a 100 year time horizon, and defined in the same reference as for the ODP mentioned above.